Research Of SH Wave Propagation Characrerics’ Influence Factors In Steel Plate And Interaction Relationship

Technology of steel plate with the SH wave detection is the research hotspot and development frontier in the field of nondestructive testing technology.However,the analyses about the influence factors of the SH wave propagation in the steel plate are not comprehensive enough,Therefore the accuracy and reliability of the detection results still remain in a certain error.For that reason,this thesis mainly researchs the effects of temperature,the external stress and boundary conditions on the propagation characteristics of SH waves in steel plate by methods of numerical calculation,simulated analysis and experimental verification for steel sheets.Firstly,this paper analyzes the principle of stimulating SH wave in the steel plate and methods of detecting the steel plate by SH wave.Then deducing the dispersion equation in wall thickness stell plate,introducing attenuation characteristics of SH wave in the steel plate.Meanwhile,clarifying the factors of affecting the propagation characteristics of SH wave.Secondly,The influence of temperature on the SH wave’s propagation characteristics is researched when SH wave is propagating in the steel plate,deriving the relationship among plate’s density,Young’s modulus,Poisson’s ratio and the temperature of the steel plate by using the theory;then the influence of temperature on SH wave’s amplitude and speed is illustrated on the basis of the relationship between the three volumes and SH wave’s amplitude and speed in the steel plate.Then,The paper bulided the model about the changes of damping coefficient when a steel plate is forced of external stress,meanwhile the relationships among the damping coefficients,magnetic induction,magnetic permeability and SH wave’s amplitude are researched.the influence of external stress on the magnetic induction and magnetic permeability is analyzed on the basis of the relationship between the three volumes and SH wave’s amplitude in the steel plate,and the same time,elaborating the influences of the damping coefficient,magnetic permeability,magnetic induction on the SH wave’s amplitude in steel plate,which describes the influence of the external stress on SH wave’s amplitude in the steel plate.Finally,on the basis of wall thickness steel plate,the vibration displacement function of SH wave is expanded to wave equation of SH wave in the wedge plate.Next,the frequency equation of SH wave dispersion in the wedge plate is derived by using coordinate rotation and appropriate boundary conditions on basis of the new vibration displacement function.Finally the influences of thickness change on SH wave amplitude is stated from the perspective of energy flow density,meanwhile the results were verified by using the finite element analysis method.